The present disclosure relates to a cleaning device and an image forming apparatus provided with the same.
As a cleaning device for an image forming apparatus such as a printer, a cleaning device provided with a cleaning roller (cleaning rotating body) has been known. The cleaning roller of the cleaning device is arranged in sliding contact with a surface of a photoconductor drum (image carrying body) in a state of carrying a toner on a surface of the cleaning roller, thereby forming a toner layer.
In such a cleaning device, the cleaning roller is in sliding contact with a surface of a photoconductor drum and polishes the surface of the photoconductor drum. In addition, in such a cleaning device, it is necessary to maintain the amount of a toner on the surface of the cleaning roller uniform in a direction of a rotational shaft, in order to reduce uneven polishing of the surface of the photoconductor drum by the cleaning roller.
Here, if the amount of the toner on the surface of the cleaning roller is too large, the toner would be electrically charged due to friction with the photoconductor drum. The electrical charge of the toner leads to damage of the surface of the photoconductor drum. This may cause drum black spots (pinholes) on a resulting image; and so-called toner fall-off, where the toner falls onto a development region.
On the other hand, if the amount of the toner on the surface of the cleaning roller is too small, an abrasive force for polishing the surface of the photoconductor drum may be insufficient.
Meanwhile, a cleaning device further including, in addition to the above-described configuration, a scraper (scraping member) that is arranged such that a front end thereof is in contact with or in proximity to the surface of the cleaning roller has been known. In this cleaning device, the scraper scrapes off the toner adhering to the surface of the cleaning roller to thereby form a thin toner layer on the surface of the cleaning roller.
In the above-described cleaning device, on the surface of the cleaning roller, there may be portions with the toner attached and portions without the toner depending on a printing ratio and a printing pattern. As a result, the amount of the toner on the surface of the cleaning roller is not uniform in the direction of the rotational shaft. This may cause uneven polishing in the direction of the rotational shaft of the cleaning roller, leading to an image defect.